The invention relates to a safety belt apparatus for motor vehicles comprising a safety belt and a deflecting device for the safety belt.
Such safety apparatuses are generally known. In the event of an accident, the safety belt apparatus must take up the energy of a vehicle occupant held by the safety belt. It is known for this purpose to integrate a torsion rod or bar into a reel which is deformed by a pulling movement of the belt induced by an accident when the reel is blocked. This kind of energy absorption requires a belt reel especially designed for this.
It is an underlying object of the invention to provide a safety belt apparatus which ensures an optimum absorption of the energy generated by the vehicle occupant in the event of an accident with the simplest possible design and a secure and reliable functioning, and in particular without impairing the function of other components of the safety belt apparatus.
According to the present invention, a safety belt apparatus is provided. The apparatus includes a safety belt and a deflecting device. The deflecting device being connected via an absorption unit to a holder which can be fastened to the vehicle, with the deflecting device being movable in an absorption direction by forces occurring relative to the holder with a pulling movement of the safety belt caused by an accident while overcoming an apposing absorption resistance of the absorption unit, but being hindered from making a movement in the absorption direction with forces occurring in normal operation, and with the absorption unit being changeable in shape by the deflecting device moving in the absorption direction in order to overcome the absorption resistance.
In accordance with the invention, a movement of the deflecting device is used for the energy absorption. For this purpose, an absorption unit is provided between the holder fixed to the vehicle and the deflecting device cooperating with the safety belt which is formed such that it prevents a movement of the deflecting device in normal operation, while allowing a movement of the deflecting device in the absorption direction with forces such as occur in an accident and which act on the deflecting device via the safety belt. The absorption unit in accordance with the invention allows the kinetic energy of the vehicle occupant in the event of an accident to be absorbed by a change in shape of the absorption unit during the movement of the deflecting device. This change in shape can generally take place in any manner, for example by material deformation, material removal, material destruction or another kind of material processing. Combinations of different material processing kinds are also possible in accordance with the invention.
The absorption device is preferably directed vertically downwardly. The deflecting device can move parallel to the vehicle side panel and parallel to a belt section extending between a belt reel and the deflecting device during the absorption of energy. It is furthermore preferably provided that the change in shape of the absorption unit is irreversible. Furthermore, the absorption unit can be deformable at least sectionally, in particular plastically, for the change in shape. In accordance with a further preferred embodiment of the invention, it is provided that the absorption unit comprises at least a part of the holder.
It is proposed in a practical embodiment of the invention that the absorption unit comprises at least one bending element, in particular a strip-like or rod-like bending element, which preferably extends approximately parallel to the absorption direction between the deflecting device and the holder.
The upper end of the bending element can be fastened to the deflecting device and the lower end to the holder so that the upper end is moved in the direction of the lower end by the movement of the deflecting device and deformation work is carried out at the bending element in this way. It is preferred if two bending elements are provided which extend parallel to one another and which are arranged at opposite sides of the safety belt.
An alternative or additional possibility for the energy absorption consists, in accordance with a further embodiment of the invention, of a connection between at least two part sections of the absorption unit which is present during normal operation being separable for the change in shape of the absorption unit. One of the part sections may be formed by a base part which can be a component of the holder.
The separation of the connection, which prevents a movement of the deflecting device in the absorption direction in normal operation, can be made in accordance with a further embodiment of the invention by an absorption section of the absorption unit being able to be torn off or out of a base part or the holder.
It is furthermore possible in accordance with the invention for an absorption section of the absorption unit to be simultaneously deformable and separable from a base part or the holder.
A further embodiment of the invention proposes that the change in shape of the absorption unit is effected by material removal. The material removal can take place, for example, by chip forming machining.
A preferred embodiment of the invention consists of the absorption unit comprising at least one recess which can be expanded for the change in shape of the absorption unit. The recess can be formed in a slit-like manner and extend parallel to the absorption direction. In accordance with the invention, the expansion of the recess can be carried out in that material bounding the recess is deformed and/or removed. An engaging section of the deflecting device or a carrier of the deflecting device serving to hold a deflection roller can engage into the recess, with said engaging section consisting of a material whose hardness is greater than that of the material bounding the recess.
The preferred material for the (s) of the absorption unit changeable in shape is steel.
The deflecting device is preferably guided at the holder, in particular parallel to the absorption direction. A defined movement of the deflecting unit is ensured in this manner despite the forces to be overcome.
Moreover, in accordance with a preferred embodiment, it is provided that the deflecting device comprises at least one deflection roller. The deflection roller can be supported at a carrier cooperating with the absorption unit.
A preferred embodiment of the invention further proposes providing a deflecting means which cooperates with the safety belt between the deflecting device and a vehicle occupant such that the safety belt extends at least approximately parallel to the absorption direction between the deflecting device and the deflecting means. The deflecting means hereby provides an optimal guiding of the forces occurring in the event of an accident into the deflecting unit via the safety belt.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed.